William Shepard Wetmore was born on 26 January 1801 in St. Albans, Vermont, the son of Seth and Nancy Shepard Wetmore. He was raised by relatives in Middletown, Connecticut, and at the age of fourteen went to work for Edward Carrington & Co., a Providence, Rhode Island mercantile trading firm which William's uncle, Samuel Wetmore, had recently joined as partner. Carrington & Co. invested in trading voyages to ports in China, the East Indies, South America, and elsewhere. In 1821 the house was reorganized to allow for the addition of a second uncle, William Willard Wetmore, as partner. William S. Wetmore embarked on his first voyage in 1815, and by the age of 20 was serving as Carrington's supercargo officer aboard the ship Fame, running between Providence and the East Indies. In 1823 Wetmore struck out on his own, partnering with the Valparaíso (Chile) import merchant Richard Alsop to create the firm Alsop & Wetmore (later Alsop, Wetmore & Cryder). The company traded between the west coast of South America, the U.S. and England with conspicuous success. In 1829 Wetmore retired from the firm, and after concluding his affairs in South America returned to the U.S. with considerable capital. Over the next several years he engaged in mercantile pursuits and sought investment opportunities in Providence and New York City. In 1833 he entered the China Trade, moving to Canton to establish Wetmore & Co. with partner Joseph Archer. He remained in China until 1839, trading tea, silks, opium and other goods to merchants in East Asia, North and South America, and Europe. Wetmore stayed active in the trade until 1847, when he withdrew his interests from his Canton and New York firms and retired to his Newport, Rhode Island mansion, Chateau-sur-Mer. He was married twice, in 1837 to his cousin Esther Phillips Wetmore (d. 1838) and in 1843 to Anstiss Derby Rogers. Wetmore died on 16 June 1862